Updated: February 13, 2007 11:50:24 AM
Also Known As: Tequila (2)
Type: Virus


The Tequila virus is an advanced memory-resident polymorphic virus, which uses several techniques to hide itself from the user. The virus body is encrypted and the virus changes itself from one infection to the next. Also, this virus uses both read stealthing and size stealthing, which means that an infected area’s size change will not be noticed during the DIR command or when a disk editing program is being used.

Antivirus Protection Dates

  • Initial Rapid Release version December 18, 2000
  • Latest Rapid Release version December 18, 2000
  • Initial Daily Certified version December 18, 2000
  • Latest Daily Certified version December 18, 2000

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Updated: February 13, 2007 11:50:24 AM
Also Known As: Tequila (2)
Type: Virus


Upon execution of an infected file, the virus will infect the master boot record only. Next time the system is rebooted this virus will be active in memory and infect any .EXE file as it is executed

When this virus triggers, it first displays in the upper left hand corner of the screen a crude graphic with the following words:

      Execute: mov ax, FE03 / int 21. Key to go on!.

      If the above instructions are executed, the following text is displayed:

      Welcome to T. TEQUILA’S latest production

      Contact T. TEQUILAP/P.o. Box 543/6312 St’hausen/Switzerland

      Loving thoughts to L.I.N.D.A.

      BEER and TEQUILA forever !

On infected hard drives a copy of the original master boot record is stored on the last physical sector of the partition of the first hard drive. This virus makes a modification to the hard drive’s partition table, reducing the size of the partition to protect this area.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

  • Use a firewall to block all incoming connections from the Internet to services that should not be publicly available. By default, you should deny all incoming connections and only allow services you explicitly want to offer to the outside world.
  • Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
  • Ensure that programs and users of the computer use the lowest level of privileges necessary to complete a task. When prompted for a root or UAC password, ensure that the program asking for administration-level access is a legitimate application.
  • Disable AutoPlay to prevent the automatic launching of executable files on network and removable drives, and disconnect the drives when not required. If write access is not required, enable read-only mode if the option is available.
  • Turn off file sharing if not needed. If file sharing is required, use ACLs and password protection to limit access. Disable anonymous access to shared folders. Grant access only to user accounts with strong passwords to folders that must be shared.
  • Turn off and remove unnecessary services. By default, many operating systems install auxiliary services that are not critical. These services are avenues of attack. If they are removed, threats have less avenues of attack.
  • If a threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
  • Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
  • Configure your email server to block or remove email that contains file attachments that are commonly used to spread threats, such as .vbs, .bat, .exe, .pif and .scr files.
  • Isolate compromised computers quickly to prevent threats from spreading further. Perform a forensic analysis and restore the computers using trusted media.
  • Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.
  • If Bluetooth is not required for mobile devices, it should be turned off. If you require its use, ensure that the device's visibility is set to "Hidden" so that it cannot be scanned by other Bluetooth devices. If device pairing must be used, ensure that all devices are set to "Unauthorized", requiring authorization for each connection request. Do not accept applications that are unsigned or sent from unknown sources.
  • For further information on the terms used in this document, please refer to the Security Response glossary.